Rolling and Moving Averages

Use rolling and moving averages to analyze data for specific time series and to spot trends in that data. When viewing these averages on a line chart, use a longer period of time to reveal long-term trends.

In IBM® Cognos® Report Studio, to add a rolling or moving average, you must create summary and custom calculations using layout expressions Insert a Query Calculation.

The Rolling and Moving Averages interactive sample report includes rolling and moving calculations. For more information about The Sample Outdoors Company, see Sample Reports and Packages.

Rolling Average

A rolling average continuously updates the average of a data set to include all the data in the set until that point. For example, the rolling average of return quantities at March 2012 would be calculated by adding the return quantities in January, February, and March, and then dividing that sum by three.

Tip: The Historical Revenue sample report in the Sales and Marketing (Cube) package also includes a rolling average. For more information about The Sample Outdoors Company samples, see Sample Reports and Packages.

Moving Average

A moving average calculates the average of a data set for a specified period. For example, the moving average of return quantities at March 2012 with a specified period of two would be calculated by adding the return quantities in February and March and then dividing that sum by two. In IBM Cognos Report Studio, you can use a prompt to specify the period.